Uuid lets you generate and validate Universally Unique Identifiers.

In its simplest form, Uuid lets you generate raw UUID formatted strings:

Uuid.raw();
// -> '6fdf6ffced7794fa407ea7b86ed9e59d'

But it has a more robust API which lets you work with UUID's as objects. Let's generate a new Uuid instance.

var uuid = Uuid.create();

We've now got an object which we can work with programmatically. Lets check the validity of our uuid using the built-in validator:

Uuid.isUuid(uuid);
// -> true

Uuid.value;
// -> '6fdf6ffced7794fa407ea7b86ed9e59d'

A handy bit of functionality is that its toString method returns the string value, so you can do handy things like this:

var itemUrl = "http://whatever.com/items/" + uuid;
// -> 'http://whatever.com/items/6fdf6ffced7794fa407ea7b86ed9e59d'

If you need a placehold Uuid, or a value to represent a non-uuid, use the static EMPTY property:

Uuid.EMPTY;
// -> '00000000000000000000000000000000'

Once you have a Uuid object, you can't change its value (thanks ES5!):

uuid.value = "go suck it, uuid!"
uuid.value;
// -> '6fdf6ffced7794fa407ea7b86ed9e59d'

To instantiate a Uuid object using an existing UUID string, use the constructor:

var uuid = new Uuid('6fdf6ffced7794fa407ea7b86ed9e59d');

You can check the equality of two different Uuid objects using the equals instance method.

Compare a Uuid object to a UUID string:

uuid.equals('6fdf6ffced7794fa407ea7b86ed9e59d');
// -> true

Compare two Uuid objects:

uuid.equals(new Uuid('6fdf6ffced7794fa407ea7b86ed9e59d'));
// -> true

Installation

You can use npm to install uuid: npm install uuid-lib

But what if I need a GUID, not a UUID?

There's also a Guid library which has the exact same functionality, but for GUID's: https://github.com/dandean/guid